Were the Rolls-Royce Vulture & Packard X-2775 Horrible Failures?

[@mandolinic]

Thanks for this. Other reviewers have posted videos mentioning the failure of the Vulture, but without going into any detail. This has filled in the gaps.

[@julianneale6128]

Im really enjoying these videos. Well presented and good for the layman to understand. Also, the topics involved are rare, and so definitely corners a niche in the market...

[@harryspeakup8452]

Not sure why you think the Vulture in the Tornado was less troublesome than in the Manchester. Only three Vulture Tornadoes ever flew -- P5219, P5224 and R7936 -- they flew very few hours, and yet of those three, one (P5219) had a complete engine failure on 31 July 1940, leading to an immediate forced landing in which it was damaged. A one in three failure rate in service in just a few flying hours is truly awful. However, could it have been made reliable? Possibly, but even then it would have still been a short-lived white elephant. One aspect you didn't mention is the poor economics of the X-24... the complexity and high component count of these X-24 engines was a direct driver of manufacturing cost and maintenance overhead. It costs very little extra to make or to service a big V-12 like a Griffon than a small V-12 like a Peregrine, as the material cost is a small proportion of the total cost - most goes into labour and machine time, which are broadly similar regardless of swept capacity. It was always going to be better to be able to procure nearly twice as many Merlins or Griffons than half as many Vultures, for the same industrial capacity and cost.

[@lesterbuckman5493]

To put it simply the Manchester placed the engine under more stress than did the fighter.

[@usernamesreprise4068]

It was always my understanding that the main reason the Vulture failed in service besides its constant catastrophic overheating problems was its sheer dead weight and bulk specifically in multi engined aircraft, It was common knowledge that while operating the aircraft in the standard set up in normal circumstances it was a good unit with huge potential.............until RAF Manchester crews started discovering to their cost that having a single engine shot to death by flak or fighters doomed the aircraft instantly as the sheer weight and size of the dead engine created so much parasitic drag the remaining engine had the utmost trouble even simply keeping the aircraft airborn, a story I heard that I am unable to fully validate was that Manchester pilots soon learned to refuse to extinguish burning engines letting them burn through engine mountings until it actually fell off which restored some yaw equalibrium and reduced wing drop, and thus enabled the pilot to get the aircraft home far more easily, all this coupled to the fact that they could produce two/almost three Merlins in the same time and tooling it took to make one vulture.....an absolute must in the middle of an all out war, do I believe the vulture could have had a future ? actually yes, but in single engined aircraft given more development time.......but that very time was a luxury we didnt have......a case in point being the Napier Sabre which was verging on being a deathtrap in its early days but went on to become a massively powerful and reliable power unit after a lot of further development ........one daydream I had years ago did however make me ponder what if they had decided to test a Manchester with FOUR vultures ? thereby not only increasing the aircrafts speed and altitude performance by a huge margin it could also have meant losing one engine would have been far less catastrophic for the crew.

[@harryspeakup8452]

@@usernamesreprise4068 but four better Merlins, like the two-stage 60 series, or four Griffons, would always have been better than four Vultures. Which is why those aeroplanes actually happened (Lincoln and Shackleton)

[@usernamesreprise4068]

@@harryspeakup8452 There must be about twenty alternative power units from the likes of Bristols etc that were available at the time, but the facts were the government read all their own prospective benefits literature and practically ordered Avro to use the Vulture, remember this was in 1938 and the merlin was just coming online with 1025 horse power, also the griffon was barely off the drawing board, and the procurement brief to Avro was for a STRICTLY two engined bomber aircraft with quite frankly far too optimistic requirements in every metric for the time (which all those "expert" politicians were ruthlessly pushing simply to save money - like ALL politicians past and present THEY knew best - until they didnt... then it was always someone elses fault) chadwick from day one knew what we would need and that it would require four engines but the government also pushed the maximum of 100 feet wingspan on him in order to fit into the out dated hangers the RAF currently had...a requirement the likes of Short Brothers (Stirling) and Handley Page (Halifax) were never held to. The Lancaster only came about when Chadwick redesigned the inboard halfs of the wings to accept four power units, my point was if the government was so determined that Avro use Vultures they SHOULD have given Avro the leeway to use four, it would have been an aircraft in a class of its own for the time.

[@osmacar5331]

Oh, very simple, weight.

[@flemmingaaberg4457]

What an incredible amount of research and information in less than 20 minutes. Always impressed with your presentations.

[@exharkhun5605]

Informative and enjoyable indeed. Corrected a lot of negative impressions/assumptions I, as a complete layman, had about X engines.

[@noonedude101]

This is a phenomenal video. Somehow, I was unaware of this engine configuration. Underrated channel. Subscribed and notifications on.

[@LetsGoAviate]

The Napier Sabre H-24 Engine Explained : kzbin.info/www/bejne/rpXOmJaOo7yirrs WW2 V-12 Engine Design Decisions Explained : kzbin.info/www/bejne/iqubp4ekoZKjd7c Aviation V-8's Explained - Good for Car's, Bad for Planes? : kzbin.info/www/bejne/rXqunKNrhsljaNE

[@jamesgoacher1606]

I think this was a good balance analysis and kept to the title of the video, an unusual feat on KZbin. Thank you.

[@terencepatrickhewitt6664]

Thank you so much for your wonderful videos. Much appreciated!

[@Rom3_29]

Doing valve lash adjustment 24 cylinder X engine must’ve been fiddling nightmare. Lubing all the bearings and pistons looks troublematic. Bottom cylinder banks would burn oil and top ones would starve of oil.

[@jbepsilon]

I think this hits the nail on the head. Without turbines arriving on the scene, engine designers would have needed to come up with layouts to use more cylinders in the quest for ever more power. Maybe some X-24, H-24, or something even more exotic like a liquid cooled radial engine (like the Zvezda M-503/504 except for aviation use) would have been developed to the point it could be considered reliable and mature. But as it was, turbines arrived, and until then the very successful and well understood V-12 layout was good enough. (yes, I'm aware of the Sabre, but given the major problems it had I wouldn't call it a particularly successful engine.)

[@ZerokillerOppel1]

Omg...these detailed HR photos you throw in...gorgeous engineering!!! Btw...I love your accent; you sound the same as the guy from the Backyard Ballistics channel here on YT...

[@PaulMcCartGuitarTracks]

Unreal man, I thought I had seen all the WW2 footage there was. Nicely done, you’ve found quite a bit I’ve never seen before.

[@gehtdianschasau8372]

Thx for the interesting video. Have fun!

[@thelandofnod123]

Thanks, informative and enjoyable. 🤓

[@michaelegan6092]

I knew Harry Lomas who was a Vulture developement engineer(also the father of Bill, the world motorcycle champion). He told me that the real problem with the Vulture was that they couldn't make the crank webs strong enough and this was the reason for it's failure.

[@waynec3563]

The Vulture design predates the Peregrine. The Vulture blocks had wider spacing than the Kestrel Peregrine. The Vultures bore spacing of 6.1in (154.94mm) was very close to the bore spacing of the Merlin, which was 6.075in (154.305mm). The Kestrel and Peregrine had a bore spacng of 5.625in (142.875mm). The Vulture did share a bore and stroke with the Kestrel/Peregrine, but not much else. One of the possible solutions for the Vulture's big end bearing issues was to revert to a fork and blade type rod system, with two sets of these per crankpin, which would have meant offsetting 2 cylinder banks from the others. This was the system used by the Allison X-4520 air-cooled X24 of the 1920s. The Vulture had been run to 2,500hp by the time of its cancellation. Possibly more. The Vulture wasn't Rolls-Royce's first X engine. In response to a government request, Rolls-Royce built the F, which would be developed into the Kestrel. They also built a test bench engine, the Eagle XVI, an X16 engine, but the airframe manufacturers preferred the V12 layout, so the engine wasn't developed. Daimler Benz also developed an X-24 engine, the DB604. But that was cancelled mid war.

[@306champion]

From the start of this video, the big thing to me was that all the successful radials had an odd number of cylinders per bank (there must be a reason for that) while this one had even numbers and uneven crank angles.

[@LetsGoAviate]

I covered this in detail my radial engine video, but in short, the odd number of cylinders per bank on a radial is required to achieve an even firing interval, and this is not possible with an even number of cylinders per bank. The X-24 is not a radial though. Each inline 6 (this engine has four inline 6's) has an even firing interval, so by using the same crankthrows on the crankshaft as an inline 6, an even firing interval is possible. A single row 4 cylinder "X" engine would not be able to achieve an even firing interval.

[@iancarr8682]

Fantastic. Can you maybe look at the Fairey Prince and Monarch engines one day?

[@AlbertRobinson-v3y]

I know these are a lot of work to produce but thank you for the education.. !!

[@commanderjameson2708]

The Germans also had the DB 606 and DB 610. The former also had considerable reliability problems in the He-177.

[@herman7661]

X-configured engines were also designed for tank use. In 1944/45 Porsche designed the Sla-16 engine (Simmering luftgekült afgeladen) X-16 (four banks of 4 cylinders), diesel engine with exhaust gas turbocharging. It was developed by the the Austrian firm of Simmering-Graz-Pauker, and was intended for use in the Panther and Tiger tanks. The 36,5 litre engine developed about 770 hp. Five engines had supposedly been built by the end of the war and hundreds of hours of bench testing performed. It has also been claimed that one engine had been installed in a Jagdtiger, for testing. The factory was unfortunately overrun by the Russians and they removed all prototypes, machine tools and records. The new Russian T-14 Armata tank is also fitted with an X-12 configured diesel engine, in this case an X-12, i.e. four banks of three cylinders each.

[@Paolo-s8p]

Thank You from Susa, Italy. Yes, here too on the Alps are aviation enthusiasts.

[@josephpacchetti5997]

This is a very interesting channel, Thank you. 👍🇮🇹 🇺🇲 subbed.

[@oml81mm]

Can't speak for the Packard engine because I know nothing about it, but yes, the RR Vulture was a huge failure.

[@observer6294]

There is at least one motorbike, that has 2 cylinders, and both pistons move same time (both go up, and both go down, same time.) But only one of those pistons press air and gas, and explode, the other one is pushing out the exhaust gas. But in both cylinders, the sparkplug will give spark. That is to make the sparking system more simpler.

[@neiloflongbeck5705]

The Vulture was also intended to power the Handley Page HP.56. But due to the Air Ministry not being certain that RR could fix the Vulture, the Ait Ministry ordered Handley Page to redesign the HP.56 to be powered by 4 RR Merlins becoming the HP.57 Halifax. This was done to ensure that one of the medium bombers designed to meet P.13/36 would be serviceable. The decision to order the Manchester and HP.56 (as back up) was taken 8n February 1937, and the decision to change engine was made in October 1937.

[@oceanhome2023]

The problem is that it needs More Moving Parts !!!

[@chrissmith2114]

Excellent piece, I often wondered why the Vulture failed ( except it had a horrible name, who would want to fly an aircraft kept in the air by vultures ).

[@roberthardy3090]

Vultures fly very well, now calling it the RR Ostrich might have some unhelpful connotations!

[@patrickradcliffe3837]

5:35 that has to be the oddest design I've ever seen. If it were me I would have siamesed the opposite banks on the same bearing similar to a merlin split rod end.

[@Flies2FLL]

Aircraft engine standard nomenclature shows the induction, the fuel system, the design of the engine, then the displacement. "O-360" means a horizontally opposed engine of 360 cubic inches, rounded to the nearest five. It doesn't show the number of cylinders. An IO-360 would be an opposed design of 360 cubic inches with fuel injection. A TSIO-520 would be a turbosupercharged fuel injected engine of 520 cubic inches. An R-670 was a carbureted 670 cubic inch radial engine that was used on the Stearman biplane. An R-3350 would be the Wright Duplex Cyclone engine that was used in the B-29 and the DC-7, but they delete the fact that this engine is not turbocharged, it is supercharged via mechanically driven blower fan. I'm not sure why they don't do this, since the naming convention states that this would be an SR-3350.

[@waynec3563]

The name convention of the 1920s-1940s?

[@Flies2FLL]

@@waynec3563 Still to this day.

[@waynec3563]

@@Flies2FLL What I am trying to say is that the military piston engine designations didn't have the prefixes I for injection or T for turbosupercharging. I believe the designation to which you refer are manufacturer designations.

[@Flies2FLL]

@@waynec3563 Those designations are industry wide, though some manufacturers take a few liberties. A TIO-540 Lycoming approximates a TSIO-520 by Continental, for example.

[@downix]

This is now the 4th X engine I have come across with the 60/120/60/120 configuration. Nobody ever seems happy with them.

[@PiDsPagePrototypes]

How does the X layout differentiate from the H layout used by BRM ?

[@waynec3563]

One crankshaft vs 2 (like in the Sabre).

[@harryspeakup8452]

... also used on the Sabre. Basically the X has one common crankshaft whereas the H engines have a separate crankshaft for each horizontally-opposed configuration, the two cranks both driving a common output shaft into the gearbox

[@womble321]

No the vulture became reliable just as they replaced it. It was found that if they were dismantled after leaving the factory they were full of metal particles. It was believed they were sabotaged but they never manged to catch the culprit.

[@garyhooper1820]

Toyota is presently enduring a major recall on V-6 engines . It was found that cleaning after machining was not thoroughly successful. Lead to thousands of failed engines . Due to debris being left inside . So perhaps it was a QC issue ?

[@EbenBransome]

Citation is needed for that. It was the Sabre that was famously being badly made till English Electric took over Napier and promptly fixed the quality problems. You don't think only one person assembled the engines?

[@waynec3563]

@@EbenBransome Also required the government to intervene and order Bristol to help with sleeve production.

[@williamzk9083]

@@waynec3563 the Vulture was in service in August 1940 on the Manchester. The Sabre in June 1941 but had to be withdrawn with problems not solved properly till June/October 1942. The Griffon was in service in Feb 1943 The Centaurus only entered service in mid 1943. The Vulture was likely the best of them and producing more power in June 1940 on the Manchester than the Griffon on the Spitfire XII in Feb 1943. The Vultures misfortune was that its maker also made the Merlin and concentrated on that.

[@waynec3563]

@@williamzk9083 They had to concentrate their resources. And one factor in continuing with the Griffon over the Vulture was that the Griffon could fit into the Spitfire, though it wasn't originally intended to do so. Some changes to the design had to be made, which delayed development,but it worked well in the Spitfire.

[@stephengardiner9867]

These engines, as well as a few OTHER beasts being developed in the U.S. and Britain might well have eventually had the bugs worked out but ..."eventually"???... during wartime??? Reliable, high performance engines with known characteristics and performance were available in numbers and most were amenable to upgrades and improvements. It is only natural that potentially more powerful but very temperamental types took back burner somewhat.

[@SW-qr8qe]

I guess the x configuration asks a lot of the crank and packs a lot of heat in too

[@danbenson7587]

Detroit Diesel built a vertical shaft submarine x 2 cycle engine. It was OK but required special lubricating oil. This engine did not have master/slave connecting rods. It had identical rods with partial bearings. Unlike the master/slave rod engines, the DD engine’s piston motions were identical.

[@mpetersen6]

It is possible to build a radial or X layout with all link rods. One system uses a fixed gear in the crankcase centered on the main bearing. The rod carrier has a gear with the same number of teeth that meshes with the fixed gear. Another system uses two extra linkage rods on the road carrier. This was developed by the Nordberg Corporation for their 12 cylinder radial stationary engines built for power house and pumping applications. Old Machine Press website for info.

[@mpetersen6]

Fairbanks Morse tried a X layout Diesel with a 60-120-60-120 layout. Also Old Machine Press. Great web site

[@danbenson7587]

@ OMP IS a great web site. It seems every possible mechanism changing pistons motion to rotation has been tried.

[@iskandartaib]

18:47 - OK, obviously the nose art states that the aircraft was named "Jill" (I wonder if the letter code was "J"), but what is "SRI.G AJAH"? the name of the pilot? What's it short for? The girl kind of reminds me of Minnie the Minx (a character in a British comic strip in one of those British comics for boys from the 1970s - can't remember if it was The Beano or The Dandy or something else) - the hair is wrong but the face is right. Same attitude.. 😁

[@EbenBransome]

Your analysis of the firing order is a good piece of work. The simple fact is that, as Calum Douglas notes in his book, by the end of the war the Merlin was producing twice as much power per litre as some other aero engines. If you have two engines of equal power and reliability, the one with fewer parts is better. We're seeing this nowadays where engines are getting smaller, with fewer cylinders and more boost. If you could get the power with a two stage supercharger on a V12, a 24 cylinder engine with double the number of pistons, rods, valves, camshafts and so on lost its point. RR agreed to drop the Vulture in WW2 and concentrate on the Merlin/Griffon, and this proved to be the correct decision. The last time and place to introduce a relatively novel engine is in a major war.

[@mpetersen6]

Plus Rolls Royce had two other 24 cylinder engines under development. The Exe and the Pennine. Both were air-cooled X layout 90° sleeve valve designs. Pratt & Whitney also had two H-24 sleeve valve engines in development.

[@waynec3563]

@@mpetersen6 The Exe was pre-war, and was cancelled at the same time as teh Vulture, at the request of Rolls-Royce. The Pennine was a 1944 design that used a single piece master rod and crankshaft built up in sections, like many of the big radials.

[@mpetersen6]

@waynec3563 Simply too many irons in the fire. The same as with P&W and Wright. Wright's case of overly complicated was the Tornado. With 42 cylinders and 21 cylinders firing per engine rotation that sound at full power would have been glorious. The Exe if it produced enough power would have been useful. Plus being air cooled it would have eliminated problems of unequal coolant flow. There were plenty of engines designed, built and tested with more than 12 cylinders. H-24s, X-24s, Hexagonal 24s plus engines with even more. The only aviation engines with 24 or more cylinders l can think of that really saw service were the R-4360, the Sabre or maybe the Eagle. The Soviets developed a Hexagonal 24 turbo compound that flew but was not used in service.

[@EbenBransome]

@@mpetersen6 Air cooling doesn't eliminate coolant flow problems, in fact it leads to real pain with ducting design and fin design, especially around heads. It's worth looking at the weird finning of radials with more than one row.

[@FREAKORZ366]

DB606-610 series boasts similar configuration and problem

[@gulfrasta5844]

I thought he was talking about a Honda K24 engine.

[@cpawp]

The x-layout could have been used as a model for a compact and powerful tank engine ...

[@mpetersen6]

If the tooling was still in existence the Curtis D-12 and the Conqueror would have been great tank engines. I think the US Army's tank development staff liked air-cooled radials for light weight and simplicity due to lack of liquid cooling.

[@wilburfinnigan2142]

You "overlooked" The Allison X24 engine and the DalmerBenz X24...Interestng Packard X24 was 2775 Cu In and they delivered to the US Navy their M2500 as a V12 for PT Boat use developed from 1250 to 1850 HP, less complicated and very successful....

[@iskandartaib]

Also interesting was the Rolls Royce Exe, a much smaller (22 liter) sleeve-valved X-24. They planned to use this in the Fairey Barracuda dive/torpedo bomber, and it got as far as flight testing. They also enlarged it into the Pennine, which had a 46 liter displacement, but this never flew. What I find strange about these two engines was the departure from the usual Rolls Royce practice of naming 4 stroke internal combustion engines for birds of prey - the Exe is a river and the Pennines is a mountain range.

[@jbepsilon]

Perhaps because the Exe and Pennine were air cooled rather than liquid cooled?

[@iskandartaib]

@jbepsilon Interesting. I totally missed that little detail. Wonder how it would have worked.

[@henkormel5610]

Alisson tried again with the double 1710. This became the 3420, in the end the engine was plagued with development problems and the programme was shut down in 1944. Mercedes coupled two DB603 engines on a common crank case ant his became I believe the DB606 it was more shaped like a W and was very prone to fires.

[@EbenBransome]

Daimler-Benz actually, which is why the engines are named DBxxx. Mercedes is for road vehicles. We should be very grateful to the German engineers who kept trying to invent new things in wartime, and thus made far more mistakes than Alied engine designers did.

[@waynec3563]

Daimler Benz coupled several engines together. The DB 601 doubled was the DB 606, the DB 605 double was the DB 610, and the coupled DB 603 was the DB 613. These were essentially two complete engines joined by a common reduction gearbox. Clutches woudl allow one engine to drive the propeller by itself. The He 177 was prone to fires because the centre exhausts of the DB 606 were vertically down, and any oil leaks woudl find their way onto the exhaust. The HE 177 also didn't have a proper firewall, so an engine fire lost more than just the engine. The original proposal for the V-3420 was for the X-3420. It was to use as many components from the V-1710 as possible, and meant that the bottom two banks could not be below horizontal. Allison countered that they could make the double Vee more powerful and with less development issues.

[@henkormel5610]

@waynec3563 There are always people who know more, thank you.

[@davidpowell7614]

Excellent, thank you. How fortuitous that the Manchester morphed in to the Lancaster!

[@roycspary8923]

bored old man with too much time to think and an engineering background, would 90degreeengines have worked?

[@AdolfGalland1968]

Great video,looks like to proves that X engine don’t work.the engine in the Russian new battle tank has a X engine and what I heard it was not reliable